This invention relates to a moist gas stream condenser assembly. More particularly, this invention relates to a condenser assembly which employs a gas stream flow path formed from a monolithic open cell foam component, the cells or pores of which form a high surface area flow path through which the moist gas stream passes. The open cell foam component includes a monolithic lattice which frames all of the cells in the foam and which serves as a heat transfer body. The foam component has a plurality of coolant passage tubes embedded inside of the foam which serve to cool the lattice and thus cause moisture in the gas stream to condense in the cells of the foam component.
U.S. Pat. No. 4,344,850, granted Aug. 17, 1982 describes a fuel cell power plant assembly which includes a condenser for removing Water from a cathode exhaust gas stream. The condenser receives the moist cathode exhaust gas stream and passes the exhaust gas stream over a coolant coil whereupon a portion of the moisture in the exhaust gas stream condenses out of the gas stream and settles into a water reservoir. The water thus collected is used to cool the fuel cell power plant active areas to prevent overheating of the fuel cell stack in the power plant and is also used to produce steam for a fuel gas steam reformer in the power plant. The coolant which is used in the condenser is air which is blown over the cathode exhaust stream. While the aforesaid condenser is servicable, it would be desirable to provide an increase in the cooled surface area on which the water will condense, and it would be desirable to be able to use other coolants in addition to air.
This invention relates to a condenser assembly which provides an increased surface area on which water can condense in the condenser, and which may be used with coolants other than air, although air may also be used as the coolant. The condenser may be used to condense water out of a moist gas stream in a fuel cell power plant, or may be used to condense water out of other types of moist gas streams. The condenser includes a very large surface area moist gas stream flow path which is cooled by a coolant fluid. The large surface area flow path is formed by a light weight monolithic open cell foam block, or a plurality of such foam blocks. The foam includes a plurality of interconnected open cells or pores which are contained in a lattice. The lattice is made from a highly efficient heat transfer material such as aluminum, stainless steel, aluminum-steel alloys, silicon carbide, nickel alloys, carbon, graphite, ceramics, or some similar suitable heat transfer material. The coolant is contained in tubes which are in direct contact with the foam monolith. To accomplish this, the tubes may be embedded in the foam monolith, or which may be sandwiched between adjacent foam monolith blocks. The coolant thus passes through the gas stream flow path and cools the lattice which forms a component of the gas stream flow path. Water will thus condense out of the moist gas stream onto the high surface area lattice in the gas stream flow path. The condensate can then fall by gravity or by other means into a reservoir adjacent to the condenser gas stream flow path. Coolants such as air, glycol, or the like can be utilized in the condenser assembly. When air is the coolant of choice, the coolant tubes may also be filled with the open cell foam in order to enhance heat transfer from the air stream to the coolant tubes.
It is therefore an object of this invention to provide an improved condenser assembly for condensing water or some other liquid out of a moist gas stream.
It is a further object of this invention to provide a condenser assembly of the character described which has an enhanced condensing surface area located in a gas flow path through which the moist gas stream is directed.
It is another object of this invention to provide a condenser assembly of the character described which includes a large surface area cooled open cell foam monolith through which the moist gas stream flows.
It is yet another object of this invention to provide a condenser assembly of the character described which includes one or more coolant fluid conduits which are in heat exchange contact with a lattice portion of the open cell foam monolith, the lattice portion forming a moisture condensing surface in the condenser.